Tests Show Radiation Causes Abnormal Fear

Grad Student's Experiments Prove Unusual Panic Follows Exposure

In the event of atomic war, what would be the reaction of irradiated combat personnel?

From the work of Ogden R. Lindsley, student at the Graduate School of Arts and Sciences, has come the first partial answer to this question. The answer also represents the first stop towards a new, behavioral test for radiation sickness.

In experiments on dogs, Lindsley has found that two hours after radiation the animals exhibit marked anxiety and fear, and are often unable to perform their accustomed tasks.

If the situation is the same for humans as present evidence indicates a soldier irradiated from the blast of an atom bomb or artillery shall, or contaminated by the radioactive dust scattered by the blast, would panic or "freeze" in a fearful battle-ground situation.

He would appear physiologically normal in all respects. His perception would remained unchanged. But he would be able to defend himself poorly, if at all.

Lindsley's findings are not all gloomy, however. The same fear that can be disastrous on the battlefield can also give the first indication of radiation sickness, days in advance of chemical tests and clinical symptoms.


With prompt identification and immediate treatment, the way may be open to the saving of thousands of lives.

Lindsley, who is a student in the Department of Experimental Psychology, carried on his experiments at the Atomic Energy Commission laboratories, directed by Dr. W. W. Jetter of the Boston University Medical School. His basic tool in these experiments was a device known as the "Skinner Box." This is a small, cubby-hole sort of enclosure, in which the dog is placed. Inside the box are a feeding trough, a metal lever, and several electrical appliances, such as lights, buzzers, and horns that can be regulated from the outside. When the box is closed, it provides a perfectly controlled environment, by which the experimenter can test a particular segment of the dog's behavior.

Lindsley's method in these experiments was an adaptation of the technique developed by B. F. Skinner, professor of Psychology, and inventor of the "Box" which bears his name. Through the study of pigeons and rats, Skinner and other experimental psychologists, have discovered means for controlling an animal's behavior, and certain laws to which that behavior conforms. It was found that an animal, who has to perform a certain task for his food will work at a highly constant pace, when he is rewarded with food at an arbitrary, erratic rate.

Skinner Box

Lindsley placed his dogs in the Skinner Box, and taught them to press the lever in order to get food. He rewarded them intermittently, however. A dog would sometimes obtain food for one or two lever presses; other times, it would take a few hundred to do the trick.

By such a procedure, Lindsley got his dogs to work at a constant rate, each pressing the lever an average of over 3,000 times an hour. The next step was to break up the hour a day during which each dog worked into parts where the dog would sometimes not get paid off, no matter how much pressing he did on the lever. For the first 15 minutes, everything continued as before--the dog worked at a constant rate, and was rewarded at erratic intervals. Then came 10 minutes where the animal would not get paid off at all. During these 10 minutes, a light in the box flashed. All the dogs eventually learned that the light was a signal that work would go unrewarded. Thus, the dogs immediately ceased pressing the lever when the light went on. Next came another 15-minute period of constant response from the dog, provoked by the arbitrary reward schedule. Following this was five minutes during which a buzzer sounded. The dogs would be fed as before if they continued to work. The dogs were not initially frightened by the buzzer, and worked while it operated. Later during the last five seconds of the buzzing, however, an extremely loud horn was turned on. Not one dog worked during the horn, even though they could get food by pressing the lever while the horn was blaring. The sounding of the horn was a fear stimulus to the dogs.

In subsequent work periods, the majority of the dogs did not work during the buzzer, which, by association with the horn, had become a learned fear stimulus.

Stabilized Behavior